Process for producing sintered alloys



, $0 scribed process for example,soja

rnocnss son Paonucme sm'rnnun ore" f .me Drawing. Application filed December 4, 1930,:Seria1 No. 499,980, and in Germany January 4:, 1830,

or drilling in order to produce their .final' form prior to becoming sintered. In most 16 cases the compression is of itself inadequate to attainthe required mechanical cohesion'. Consequently, such articles have hitherto been seed oil, pitch Japanese wood oil, 1, andothers.

' The varnishderivatives of such" oils are also capable of application with'especial adpresintered, which is to 'say preheated to aboutared glow. v 15 That method of enhancing cohesion 'is cumbersome and requiresspecial furnaces. Moreover it has the drawback attending the fact that most of themetals or'their metaliform combinations like the carbides, nitrides 2 and others react more or less with the furnace gases while 'so glowing and can 'sufier changes leastways superficially in their structure.

According uniform distribution occurs, the accomplish ment of which is favored if the metal pow- 35 ders are not entirely dry, instead, manifest a moisture of. about one to two per cent.

After pressing the articles, atmospheric oxygen causes an oxidation and polymerization of the unsatiated'acids whereupon they s'tifien completely-in a few hours. The oxi '-,dation can be curtailed an hour by conducting warmed air of about oneto two hundred degrees to the pieces. Thereafter the articles 45 are so hard and edge sec'ure that one may,

subject [them to every requiredoperation without danger of fracture.

A large number of oils containing ated acids are available foruseinthis de to the present invention, the 3 articles are strengthened after com ression Such oils which contain 'the addition of the oils vantage; generally an oil is better for this process indirect proportion as its increased iodine content.

The process may be modified by spraying the oil upon the press-formed pieces, or by effecting an incorporation through a daubing co operation; in either case, the absorptionability of the pieces can be enhanced'if the oils are applied with 'athin fluid vehicle like benzine oremulsions. This method of impregnation of the articles is less exact than ea.

before pressing. -Iclaim: 1. The process for producing sintered I bodies of powdered metals, comprising, uniformly impregnating a slightly .moistened 7o powdered metallic aggre ate with a vegetable oil containing unsatiat'e fatty acids, forming the aggregate :by pressing whileat a'tmospheric; temperature, allowingit to stiffen .byxatmospheric exposure'whereby to increase as the cohesiveness of the formed body and then sintering,

2. The process for producing sintered' v bodies of powdered metals, com risin the homogeneous mixing of a vegetab ing fattyacid and iodine content with ow-- dered metals, forming the mixture'by pressing into a-body of desired shape, allowing oxidation and polymerization to occur in the 1 presence of warmed air and subsequently 9e sintermg.

Signed this 3 1stday ofOctober 1930. RICHARD-1t. wilnrnn.

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